Wire feed apparatus



June 3, 1969 J. c. JEANNETTE WIRE FEED APPARATUS Sheet Filed April 15,1966 FIG. 2

FIG. 8

INVENTOR JOSEPH C. JEANNETTE June 3, 1969 J. c. JEANNETTE 3,447,730

WIRE FEED APPARATUS Filed April 15, 1966 Sheet 2 of s m "w L 4% INVENTORJOSEPH C. JEAN/VETTE June 3, 1969 J. c. JEANNETTE WIRE FEED APPARATUSSheet Filed April 15, 1966 FIG. 5c

FIG. 7

FIG. 5b

INVENTOR JOSEPH c JEA NNETTE United States Patent US. Cl. 226-176 9Claims ABSTRACT OF THE DISCLOSURE A four-roll wire feed device adaptedto drive wires of varying diameters. One of a pair of spring biasedrolls is split perpendicular to its axis whereby variable size and/ornumber of spacers may be inserted to accommodate varying wire diameters.

This invention relates to apparatus for feeding wire and the like.

This invention also relates to an improved wire feed apparatus for usein an electric arc welding system. More particularly, this inventionrelates to a 4-roll wire feed device that can accommodate various sizesof wires without replacement of parts.

The basic 4-roll wire feed device is well known in the prior art. Atypical device is described in United States Letters Patent No.2,032,260 granted to V. J. Chapman on Feb. 25, 1936. The device isnormally used to automatically advance a wire electrode in an arcwelding sys tem. Heretofore, whenever a different size of electrode wasto be used, the 4-roll wire feed device had to be replaced or rebuilt inorder to accommodate the new electrode. This involved considerable timeand expense and greatly increased the difliculties involved in onlocation welding. The welder would have to carry around either amultiplicity of wire feed devices or in the alternative a plurality ofdifferent sized drive rollers so that he could weld with different sizedwire electrodes.

It is, therefore, an object of this invention to provide a single wiredrive mechanism which will accommodate various sizes of electrodes.

Another object of the invention is to provide an improved wire drivemechanism in which the drive and the driven rollers are capable ofengaging all sizes of wire electrode.

Another object of the invention is to provide an improved wire drivemechanism which will accommodate different size wire electrodes withoutreplacement of parts.

Other objects, features and advantages will appear or be pointed out asthe description proceeds.

In the drawings;

FIGURE 1 is an elevational view showing an illustrative embodiment ofthe invention;

FIGURE 2 is a view partly in section, partly broken away, taken on theline 22 of FIGURE 1;

FIGURE 3 shows an end elevational view of the device shown in FIGURE 1;

FIGURE 4 shows a plan view, partly in section, partly broken away, ofthe drive mechanism for the device;

FIGURES Sa-Sf illustrate diagrammatically an embodiment of the inventionin which various pairs of spacers are used to separate the halves of thedrive rollers;

FIGURE 6 illustrates diagrammatically an embodiment of the invention inwhich a single spacer is used to separate the halves of the driverollers;

FIGURE 7 illustrates diagrammatically an embodiment of the invention inwhich the drive rollers are spring loaded so that the rollers may beforced apart to accommodate various sizes of wire electrode;

FIGURE 8 illustrates the preferred form of a spacer which is to be usedin certain embodiments of the invention;

FIGURE 9 illustrates a side view of the spring assembly; and

FIGURE 10 illustrates a plan view of the spring assembly.

FIGURE 1 shows a wire feed assembly having a rear plate 1, left sideplate 2 and a right side plate 3. The plates are preferably formed aspart of an integral casting.

A cylindrical pin 6 is mounted in the rear plate 1 and extends forwardlytherefrom. Pivotally mounted on this pin are a pair of roller brackets,designated 7, 8 respectively. A grip ring 9 locks the brackets on thepin 6. The brackets are partially channel shaped as shown in FIGURE 2and have bifurcated extensions with circular openings to ride on the pin6. Each of the brackets is spring loaded as shown in FIGURE 3. A leafspring 13 is pivotally mounted on a pin 14 for substantially horizontalmovement. The spring may be locked in position by means of a catch 15.The spring may be locked in either recess 17 or 18 in order to provide adegree of adjustment which will be more particularly described below.The bracket 8 is spring loaded in the same manner as bracket 7. Eachcatch 15 is mounted on an end plate by means of screws 16.

On the lower portion of each bracket is mounted a pin 20, 21 which islocked in place by means of grip rings 22, 23 which are in turn held inposition by means of screws 24, 25. Rotatably mounted on the pins 20 and21 are pressure rollers 27, 28 and gears 29, 30. The pressure rollersmay be smooth or serrated depending on the type of wire to be driven.The gears and rollers are preferably made from the same piece. Thrustbearings 31 and 32 are located between the roller face and the bracketand between the gear face and bracket.

The lower drive roll mechanism which cooperates with the upper pressureroller mechanism will now be described. Fixedly mounted in the rearplate at spaced locations are pins 35, 36. The mechanism associated withonly one pin will be described, it being understood that the other driveroll mechanism is of the same form. On each pin is rotatably mounted adrive roll retainer having a geared portion 41, a cylindrically shapedportion 42 and a threaded portion 43. Slidably mounted on the portion 42is an annular spacer 45, and split drive roll members 46, 47. The spacerand drive rol-l members are keyed 48 to the portion 42 to preventrelative rotation therebetween. An annular spacer ring 44 is placedbetween the members 46 and 47 but is not keyed on 48. The relationshipbetween the roll members and spacers will be described in detail belowwith reference to FIGURES 5a-7. The roll members and spacers are lockedon the portion 42 by means of nut 50 which is screwed on threadedportion 43. A bushing 51 and grip ring 52 serve to lock the wholeassembly on the shaft 36. As shown in FIG- URE 2 the gears 41 and 30 aredrivingly interconnected. Thus, viewing FIGURE 1, counter clockwiserotation of gear 41 results in clockwise rotation of gear 30. The otherpair of gears associated with shafts 20 and 35 are drivinglyinterconnected in the same manner.

The drive mechanism for the device is illustrated in FIGURE 4. An inputshaft 55, which is connected to a motor or other suitable power source,is drivingly connected to shaft 61 through a gear reduction unit 56. Theshaft 61 is drivingly connected to shaft 60 by means of a bevel gearunit indicated at 57. Suitable bearing means 58 support shaft 60. A gear59 is rigidly fixed to shaft 60 and is in driving relationship with thegears 39' and 41. Thus the drive mechanism drives both pairs ofcooperating rollers. The drive mechanism and associated 3 motor 60 ismounted on the rear plate 1 by means of bolts 61.

The operation of the illustrated wire feed assembly may be described asfollows: A wire is thrust through the opening 65 and into the spacebetween the pressure roller 28 and the drive roll members 46 and 47. Asshown in FIGURE 2 the drive roll members have a beveled peripheral edgeon each face of the roll member. The angle a of the bevel as shown inFIGURE 5a is approximately 13. The space resulting from the bevelsaccommodates a wire 85 as shown in FIGURE 5a. The wire is drivingly fedthrough both pairs of rollers and exists through opening 66.

As illustrated in FIGURE 1, a downward force is exerted on the wire bymeans of pressure rollers 27, 28. Brackets 7 and 8 are forced downwardlyby means of the springs 12 and 13. The springs are positioned in outerrecesses 17 as shown in FIGURE 1. If less force is to be exerted on thewire, the springs may be located in recesses 18. This arrangementconstitutes a simplified and more reliable method of applying variableforces to a wire than has heretofore been used.

The springs each comprise a .pair of substantially flat leaves 90, 91,preferably made from spring steel. The leaves are prestressed so thatthey assume a slightly arcuate form, as illustrated in FIGURE 9. Theleaves are riveted 92 together at one end and are drilled 93 at theother end to accept the pin 14. The springs are assembled on the wirefeeder so that the convex surfaces engage the roller brackets 7, 8. Thuswhen wire is fed into the machine the springs are deflected upwardly andare thereby flattened out as shown in FIGURE 3. The rate of the springmust of course be selected bearing in mind the load which the wire cantolerate without being deformed. Constant rate springs are preferred.Another important feature of the spring assembly is that it is selfadjusting and therefore may accommodate many wire sizes. The followingcharts illustrate the relationship between various wire diameters andthe load on the wire when the spring is locked in recess 17 and when inrecess 18. The recess 17 is usually used when hard wires are to be fedsince it affords greater loads on the wire. Note that the recess 17 isslightly lower than recess 18 in bracket 15. The recess 18 is used forsoft wire and for many of the cored wires.

SPRIN G IN RECESS 18 Pressure at Lead on Wire diameter (inches) spring(lbs) wire (lbs) As shown in the above charts many different wire sizescan be used in the feeder without adjusting the spring mechanism. Thisself adjusting feature is extremely important in that considerable timeis saved when changing wires in that the spring pressure need not bereset. The self adjusting spring mechanism cooperates with the splitroller mechanism which will hereinafter be more particularly describedto accommodate many wire sizes.

The type of mechanism illustrated in FIGURE 1 is especially suited foruse in feeding electrode wire in arc welding systems. In this type ofenvironment the motor speed is controlled by well known systems whichmain- 4 tain constant arc voltage by varying the electrode feed rate.

The spacer mechanism which is an important part of the wire feedassembly will now be described in detail. Heretofore, the lower driveroll members were grooved in a peripheral sense in order to accommodatethe wire. This is clearly illustrated in the Chapman patent, notedabove. This type of construction has one obvious disadvantage, and thatis that only one size of wire may be effectively handled therein.Attempts to feed a larger size wire will result in wire deformation andif smaller size wire is used, it will not be transmitted through themechanism.

In the embodiment shown in FIGURE 2, a pair of spacers are utilized, one44 located between the drive roll members and the other 45 locatedinwardly thereof. If the operator desires to accommodate a larger wire,he merely removes the nut 50 and rolls 46, 47 and then places theadditional spacer 45 between the rolls and then he reassembles the drivemechanism, Thus there is no need to carry additional drive rollers whenthe use of different sizes of wire is contemplated. Spacer 45 isillustrated in FIGURE 8. The spacer 44 may be annular in form and neednot be keyed to the key 48.

Another embodiment of the spacer mechanism for adjusting the lower guiderollers 46, 47 is shown more clearly in FIGURES 5a-5f. Thecircumferential portion of each guide roller is beveled 73, 74 toreceive the wire electrode. Pairs of different sized spacers 76410 aremounted on opposite sides of the rollers. If the operator of the devicedesires to change the size of the wire electrode he merely removes thenut 50 and rearranges the rollers 46, 47 and associated spacers so thatthe size of wire he now wants to use may be accommodated. When pairs ofspacers of equal size are used as shown in FIGURES 5a5f, the centerlines of all the various sizes of wire will be in the same plane. Thus,the rollers 46, 47 will each be moved axially the same amount and thepoint of contact 72 of the wire on the pressure roller 28 will always bethe same. FIGURES Sb-Sj illustrate schematically the pressure rollers indifferent adjusted positions.

The following is a chart illustrating the relationship between spacerthickness and wire size:

Spacer thickness Wire size, =|=.003 inches Quantity inches When pairs ofspacers are used the wire always exits at the same point through opening66 and the wire will be fed along a straight path. This is an extremelyimportant advantage in that the wire will not be deformed. If the pointof contact 72 is shifted, then the wire will be bent and assume a castsince it enters opening 66 at an angle.

When single spacers of various sizes are used as shown in FIGURES 2 and6 the point of contact 72 will shift and one roller will remain fixedrelative to the other.

A further modification is schematically illustrated in FIGURE 7. In thismodification springs are used to replace the spacers. Helical springs86, 81 are positioned between bac-king plates 82, 83 and the rollers 46,47.

The rollers 46, 47 can move axially against the spring pressure toaccommodate various sizes of wire electrode. The spring loadedembodiment has definite advantages in that it is not necessary to removethe nut 50 and then rearrange the rollers. The operator merely thruststhe wire through the inlet fitting 65 and into the grooved area betweenthe rollers at which time the rollers will separate and adapt to thesize of the wire. When the springs 86, 81 are of equal force the pointof contact 72 will remain the same for all sizes of wire. Various typesof springs may be employed for this purpose. For example, wave typesprings or the Belleville type are suitable due to their size, shape andstrength. The wave bent type was found especially suited for small sizesof wire.

Initially the feasibility of using split drive rollers was tested on aworkbench set up in which the pressure rollers were forced downwardly bymeans of weighted devices. The weights were of course known andtherefore the pressures required to feed various sizes of wire could bedetermined. Excessive pressures cannot be tolerated in this type offeeder due to the resulting wire deformation. Furthermore, this devicemust often be used to feed cored wire which can only accept mediumcompressive forces. The results of these tests showed that the splitroller technique did not necessitate the use of excessive compressiveforces to feed the wire and that soft wire and cored wire could be fedwithout deformation.

The apparatus described above is especially suited for use in an arcwelding system but can of course be used in any type of wire feedingsystem.

While illustrative forms of apparatus in accordance with the inventionhave been described and shown herein, it will be understood thatnumerous changes may be made without departing from the generalprinciples and scope of the invention.

What is claimed is:

1. A wire feed mechanism comprising, a housing means, a plurality ofroller means rotatably mounted on said housing, one of said roller meansbeing split perpendicular to its axis of rotation, drive means drivinglyconnected to at least one of said roller means, said roller means beingclosely spaced so as to abut a wire thrust therebetween, meanscomprising spacers to adjust the position of said split roller meansalong its axis of rotation so that various sizes of wires may beaccommodated in said wire feed mechanism.

2. The feed mechanism described in claim 1 in which the spacers arecomprised of pairs of equal size.

3. The feed mechanism described in claim 1 in which the spacers are ofdiffering sizes.

4. A wire feed mechanism for use with electric arc welding apparatuscomprising a housing means, a pressure roller housing adjustably mountedin said housing means, a first roller rotatably mounted in said pressureroller housing, a second roller rotatably mounted on axle means in saidhousing means, said first and second rollers being closely spaced so asto abut a wire thrust therebetween, drive means for said rollers,transmission means interconnecting said rollers, said second rollerbeing split along a plane perpendicular to the axis of rotation of the 6roller, said split roller being axially adjustable along said axle meansto accommodate various sizes of wire and means to maintain the positionof said split roller in said adjusted positions.

5. The feed mechanism described in claim 4 in which the positionmaintaining means comprises pairs of spacers of equal size.

6. The feed mechanism described in claim 4 in which the positionmaintaining means comprises spacers of differing size.

7. The feed mechanism described in claim 4 in which the positionmaintaining means comprises resilient means coacting with said splitroller.

8. The feed mechanism described in claim 4 in which the pressure rollerhousing comprises a bracket member pivotally mounted on said housingmeans, a spring member pivotally mounted on said housing means andengaging said bracket member, an upstanding bracket having recessesmounted to said housing means adjacent said bracket member, said springmember being capable of selective locking engagement with any of saidrecesses.

9. A wire feed mechanism for use with an electric arc welding apparatuscomprising a housing means, a pressure roller housing movably mounted insaid housing means, a first roller mounted in said pressure rollerhousing, a second roller mounted in said housing means in closeproximity to said first so as to abut a wire thrust therebetween, drivemeans interconnecting said rollers, spring means mounted on said housingmeans forcing said first roller toward said second roller, said springmeans comprising a relatively thin substantially flat spring member andis pivotally mounted on said housing means and is capable of beinglocked in one of a plurality of recesses in said housing means.

References Cited UNITED STATES PATENTS 1,246,863 11/ 1917 Bright-man22'6-184 X 3,022,929 2/1962 Myers et 'al 226-185 X 3,093,285 6/1963Leaming et al. 226-184 1,228,178 5/1917 Brooker -171 2,091,021 8/1937Stevens 226-187 X 3,107,291 10/1963 Evans et a1. 219- 3,331,545 7/1967Olivieri 226-187 ALLEN N. KNOWLES, Primary Examiner.

US. Cl. X.R.

